Touch sensor and method for preparing the same

ABSTRACT

The present invention provides a touch sensor and a method for preparing the same. The touch sensor includes a substrate, an electrode layer located in a window area, and a frame trace located in a frame trace area. The frame trace includes a plurality of metal wires. Each metal wire includes a metal wire body electrically connected to a corresponding electrode in the electrode layer and an insulation layer wrapped around an outer periphery of the metal wire body. In this way, the width of the frame trace area can be further reduced.

TECHNICAL FIELD

The present invention relates to the field of touch screens, and inparticular, to a touch sensor and a method for preparing the same.

BACKGROUND

With the continuous development of touch screen devices, touch deviceshave been rapidly promoted. At present, touch devices have increasinglyhigh requirements for lightness, thinness, and high quality. The narrowbezel technology has always been a technology for improving producttexture. However, a larger screen indicates a larger number of frametraces and a wider overall frame. However, a narrower frame of the touchdevice has a higher requirement for the frame traces of the touchsensor.

As shown in FIG. 1, the existing process scheme for the frame traces ofthe touch sensor is mainly a printing process, a laser process, and ayellow light process. Regardless of which one process above, narrowingthe frame will face the problem of a large increase in costs and a largedecrease in the yield. In addition, an insulating area 2 is formedbetween metal wires 1′ of the frame traces, so as to prevent shortcircuits as result of the contact between adjacent metal wires.Excessively large width and spacing between the metal wires of the frametraces may easily cause an excessively wide frame of the touch displaypanel.

To this end, it is necessary to provide a new touch sensor and a methodfor preparing the same to resolve the foregoing problem.

SUMMARY

The present invention is intended to provide a touch sensor and a methodfor preparing the same.

To achieve the foregoing objective, the present invention adopts thefollowing technical solutions:

A touch sensor, comprising a substrate, an electrode layer located on awindow area of the substrate, and a frame trace located in a frame tracearea of the substrate, the frame trace comprises a plurality of metalwires, and each metal wire comprises a metal wire body electricallyconnected to a corresponding electrode in the electrode layer and aninsulation layer wrapped around an outer periphery of the metal wirebody.

As a further improvement of the present invention, a distance betweenadjacent metal wires is in a range of 0-20 um.

As a further improvement of the present invention, the plurality ofmetal wires are arranged in parallel or in a stacked manner.

As a further improvement of the present invention, a material of theinsulation layer is acrylic resin, epoxy resin, polyurethane resin,polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethylmethacrylate, polyester, polyoxymethylene, polyamide, or polyphenyleneether.

As a further improvement of the present invention, the frame trace areahas a conductive silver paste electrically connected to the electrode inthe electrode layer, and the conductive silver paste contains apropylene glycol monomethyl ether solvent, a benzene solvent, a butylcellosolve acetate (BCA) solvent, a diethylene glycol butyl etheracetate solvent, a carbitol acetate solvent, or an isophorone solvent.

To achieve the foregoing objective, the present invention also providesa method for preparing a touch sensor, the method comprising thefollowing steps:

S1: forming an electrode layer in the window area of a substrate;

S2: Arranging the frame trace for electrical connection with theelectrode layer in the frame trace area of the substrate, wherein theframe trace comprises a plurality of metal wires, and each metal wirecomprises a metal wire body and an insulation layer wrapped around anouter periphery of the metal wire body; and

S3: removing the insulation layer of the lapping portion on the metalwire, and electrically connecting the lapping portion to thecorresponding electrode in the electrode layer.

As a further improvement of the present invention, step S2 specificallycomprises:

S21: A conductive silver paste electrically connected to the electrodeis formed in the frame trace area and an adhesive layer on theconductive silver paste; and

S22: arranging the metal wire on the adhesive layer; or

step S2 specifically comprises:

S2a: A conductive silver paste electrically connected to the electrodeis formed in the frame trace area;

S2b: forming an opening in the adhesive layer;

S2c: arranging metal wires at a position of the adhesive layercorresponding to the frame trace area, wherein at least part of thestructure of the lapping portion is located in the opening; and

S2d: Assembling the adhesive layer with metal wires onto the substrate;

the opening corresponds to the conductive silver paste.

As a further improvement of the present invention, step S3 specificallycomprises:

removing the insulation layer of the lapping portion by means ofwelding, and welding the lapping portion and the correspondingconductive silver paste together, so that the lapping portion iselectrically connected to the corresponding conductive silver paste.

As a further improvement of the present invention, the method forpreparing a touch sensor further comprises S4 after step S3: dispensingor printing a protective adhesive at a joint between the lapping portionand the conductive silver paste, wherein the protective adhesive issilver paste.

As a further improvement of the present invention, step S2 specificallycomprises:

S2A: A conductive silver paste electrically connected to the electrodeis formed in the frame trace area and/or A conductive silver paste canelectrically connected to the electrode is formed on the adhesive layer,wherein the conductive silver paste contains a propylene glycolmonomethyl ether solvent, a benzene solvent, a BCA solvent, a diethyleneglycol butyl ether acetate solvent, a carbitol acetate solvent, or anisophorone solvent;

S2B: forming an opening in the adhesive layer;

S2C: arranging metal wires at a position of the adhesive layercorresponding to the frame trace area, wherein at least part of astructure of the lapping portion is located in the opening, and thematerial of the insulation layer is acrylic resin, polyurethane resin,epoxy resin, polyethylene, polypropylene, polyvinyl chloride,polystyrene, polymethyl methacrylate, polyester, polyoxymethylene,polyamide, or polyphenylene ether; and

S2D: Assembling the adhesive layer with metal wires onto the substrate;

the opening corresponds to the conductive silver paste, and theconductive silver paste in contact with the lapping area is ato-be-cured conductive silver paste.

As a further improvement of the present invention, step S3 specificallycomprises:

the lapping portion is in contact with the to-be-cured conductive silverpaste; and

During the curing of the conductive silver paste, the conductive silverpaste dissolves the insulation layer of the lapping portion, and thelapping portion and the conductive silver paste are cured together.

As a further improvement of the present invention, step S2 specificallycomprises:

S2x: A conductive silver paste electrically connected to the electrodeis formed in the frame trace area;

S2y: arranging metal wires at a position of the adhesive layercorresponding to the frame trace area, wherein

the lapping portion corresponds to the conductive silver paste.

As a further improvement of the present invention, step S3 specificallycomprises:

An opening corresponding to the conductive silver paste is formed on theadhesive layer, and remove the insulation layer of the lapping portion;and

Assembling the adhesive layer with metal wires onto the substrate, thelapping portion is electrically connected to the correspondingconductive silver paste.

As a further improvement of the present invention, the method forpreparing a touch sensor further comprises S4 after step S3: dispensingor printing a protective adhesive at a joint between the lapping portionand the conductive silver paste, wherein the protective adhesive issilver paste.

Beneficial effects of the present invention are as follows: the touchsensor in the present invention uses metal wires with an insulationlayer to replace the silver paste in the traditional process to formframe traces, so as to prevent the electrical contact between adjacentmetal wires and cause short circuits. In this way, the distance betweenadjacent metal wires may be 0, and even a plurality of metal wires maybe stacked on each other. Therefore, the width of the frame trace areacan be further reduced without increasing the preparation costs of thetouch sensor

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of existing frame traces.

FIG. 2 is a schematic structural diagram of frame traces of a touchsensor according to the present invention.

DETAILED DESCRIPTION

In order to enable those skilled in the art to better understand thetechnical solutions of the present invention, a touch sensor and amethod for preparing the same provided in the present invention arefurther described below with reference to the accompany drawing 2 andspecific implementations. Apparently, the described implementations aremerely some but not all of the implementations of the present invention.Other implementations obtained by a person of ordinary skill in the artbased on the implementations of the invention without creative effortsshall fall within the protection scope of the present invention.

The present invention provides a touch sensor, including a substrate, anelectrode layer formed on the substrate, and a frame trace (notnumbered) electrically connected to the electrode layer. The electrodelayer is provided with an electrode electrically connected to the frametrace.

Specifically, the substrate includes a window area and a frame tracearea located on a periphery of the window area. The electrode layer islocated on the window area, and the frame trace is located in the frametrace area. Those skilled in the art may also understand that an areawhere the electrode layer is located constitutes the window area of thetouch sensor, and the area where the frame trace is located constitutesthe frame trace area of the touch sensor.

Further, as shown in FIG. 2, the frame trace includes a plurality ofmetal wires 1, and each metal wire 1 includes a metal wire bodyelectrically connected to a corresponding electrode and an insulationlayer wrapped around an outer periphery of the metal wire body, so as toprevent short circuits as a result of electrical contact betweenadjacent metal wires.

Further, a distance between adjacent metal wires 1 is in a range of 0-20um, and may be even 0 without causing a short circuit, so as to reducethe width of the frame trace area.

Further, the plurality of metal wires 1 are arranged in parallel or in astacked manner, or the frame traces are formed by stacking a pluralityof metal wires 1 to further reduce the width of the frame trace area.

It may be understood that the above stacking refers to a plurality ofmetal wires 1 stacked on each other in a height direction. The stackingincludes but is not limited to two metal wires 1 stacked one on top ofthe other, or metal wires 1 arranged in parallel on an upper layer andmetal wires 1 arranged in parallel on a lower layer are arrangedalternately, so as to further reduce the width of the frame trace areawithout increasing the preparation costs of the touch sensor.

In addition, a diameter of the metal wire 1 itself is not greater than15 microns. In this way, it not only can ensure effective electricalcontact, and can further reduce the width of the frame trace areawithout increasing the preparation costs of the touch sensor.

In a specific implementation, the metal wire 1 is a copper wire. That isto say, the material of the metal wire body is copper, which hasrelatively low costs. Certainly, the metal wire may alternatively beother conductive metal wires such as gold wire, silver wire, or thelike.

In a first implementation of the present invention, a method forpreparing a touch sensor is further provided. The method includes thefollowing steps.

S1: Forming an electrode layer in the window area of a substrate.

S2: Arranging the frame trace for electrical connection with theelectrode layer in the frame trace area of the substrate, where theframe trace includes a plurality of metal wires 1, and each metal wire 1includes a metal wire body and an insulation layer wrapped around theouter periphery of the metal wire body.

S3: Removing the insulation layer of the lapping portion on the metalwire 1, and electrically connect the lapping portion to thecorresponding electrode in the electrode layer.

S1, S2, and S3 are just for the convenience of description and do notrepresent the sequence of steps. The sequence of step S1 and step S2 canbe transposed, and step S3 is located after the two steps. In addition,the step numbers in this application are all for convenience ofdescription, and unless otherwise specified, each number does notrepresent a sequence.

Step S1 specifically includes: performing a patterned etching process ona substrate having a conductive film, so as to form a patternedconductive film in the window area of the substrate and form theelectrode layer.

In a specific implementation, the etching process is laser etchingprocess. Certainly, the present invention is not limited thereto.

In this implementation, step S2 specifically includes the followingsteps.

S21: A conductive silver paste electrically connected to the electrodelayer is formed in the frame trace area of the substrate and an adhesivelayer on the conductive silver paste.

S22: Arranging the metal wire on the adhesive layer.

Specifically, the adhesive layer in step S21 is a pressure-sensitiveadhesive printed to the frame trace area to fix the metal wire 1 to theframe trace area. Certainly, the present invention is not limitedthereto.

Step S22 specifically includes: arranging the metal wire on the adhesivelayer by using a wiring machine.

In addition, it may be understood that when the metal wire is arrangedon the adhesive layer, the lapping area on the metal wire is made tocorrespond to the corresponding conductive silver paste, so that thelapping area is electrically connected to the conductive silver paste,thereby achieving the electrical connection between the metal wire andthe electrode. The electrode in the electrode layer is led out bydisposing the conductive silver paste, so as to increase the contactarea of the electrical connection between the electrode and the metalwire, thereby enhancing the stability of the electrical connectionbetween the metal wire and the electrode.

Based on the above first implementation, step S3 specifically includes:removing the insulation layer of the lapping portion by means ofwelding, and welding the lapping portion and the conductive silver pastetogether, so that the lapping portion is electrically connected to thecorresponding conductive silver paste.

In this implementation, the insulation layer has thermal decompositionproperties. For example, a material of the insulation layer may beacrylic resin, epoxy resin, polyurethane resin, polyethylene,polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate,polyester, polyoxymethylene, polyamide, polyphenylene ether, or thelike. In this way, during the welding, under the action of the weldingheat, the insulation layer on the lapping portion can be removed, andthe lapping portion and the conductive silver paste can be weldedtogether to achieve the electrical connection between the lappingportion and the corresponding conductive silver paste.

Further, the method for preparing the touch sensor further includes stepS4 after step S3: dispensing or printing the protective adhesive at ajoint between the lapping portion and the conductive silver paste. Inthis way, a solder joint between the lapping portion and thecorresponding conductive silver paste is protected, and the stability ofthe electrical connection between the lapping portion and thecorresponding conductive silver paste can be enhanced.

Specifically, the protective adhesive is silver paste.

Specifically, in this implementation, a silver paste is dispensed orprinted at the joint between the lapping portion and the correspondingconductive silver paste by using a dispenser or a screen printingprocess, which is convenient to operate. Certainly, the presentinvention is not limited thereto.

In a specific implementation of preparing a touch sensor according tothe first implementation of the present invention, the preparationmethod is as follows.

A substrate having a conductive film is prepared or a conductive film isformed on the substrate. The conductive film is etched by using thelaser process to form an electrode layer in the window area of thesubstrate. After the etching by using the laser process, the conductivesilver paste electrically connected to the electrode in the electrodelayer is printed in the frame trace area of the substrate. After theconductive silver paste is printed, the pressure-sensitive adhesive isprinted on the frame trace area, and then copper wires are arranged onthe pressure-sensitive adhesive by using a wiring machine. After thecopper wires are arranged, the insulation layer of the lapping portionof the copper wire is removed by means of welding, at the same time thelapping portion and the corresponding conductive silver paste are weldedtogether and connected. Finally, a silver paste is dispensed, by using adispenser, at a joint between the lapping portion of the copper wire andthe conductive silver paste to protect a solder joint between thelapping portion and the conductive silver paste.

It may be understood that a touch display screen includes two touchsensors. One touch sensor serves as a driving layer, and another servesas a receiving layer, to sense human body touch signals in cooperationwith work to complete the positioning of the touch position.

In addition, the methods for preparing the driving layer and thereceiving layer are the same, and both the driving layer and thereceiving layer can be prepared by using the preparation method in theabove first implementation.

In the second implementation of the present invention, the method forpreparing a touch sensor in the second implementation differs from thatin the first implementation only in step S2, and the other steps S1, S3,and S4 are the same. Details will not be described herein again.

In this implementation, step S2 specifically includes the followingsteps.

S2a: A conductive silver paste electrically connected to the electrodeis formed in the frame trace area.

S2b: Forming an opening in the adhesive layer.

S2c: Arranging metal wires at a position of the adhesive layercorresponding to the frame trace area, where at least part of thestructure of the lapping portion is located in the opening.

S2d: Assembling the adhesive layer with metal wires onto the substrate.

The opening corresponds to the conductive silver paste.

S2a, S2b, S2c, and S2d are just for the convenience of description anddo not represent the sequence of steps. The sequence of step S2a andstep S2b can be transposed or can be performed simultaneously, and thesequence of step S2a and step S2c can be transposed or can be performedsimultaneously, as long as it is ensured that the opening finallycorresponds to the conductive silver paste. As a result, step S2c isafter step S2b, and step S2d is after step S2c. In addition, the stepnumbers in this application are all for convenience of description, andunless otherwise specified, each number does not represent a sequence.

Specifically, the adhesive layer in the second implementation isoptically clear adhesive (OCA), so as to be easily bonded to othercomponents of the touch display screen by means of bonding. For example,the touch display screen includes two touch sensors. One touch sensorserves as a driving layer, and another serves as a receiving layer, tosense human body touch signals in cooperation with work to complete thepositioning of the touch position. In this way, the OCA can bond thedriving layer and the receiving layer.

Certainly, the present invention is not limited thereto. For example,the adhesive layer may also be a pressure-sensitive adhesive film.Compared with the adhesive layer being OCA, the advantage is that thepressure-sensitive adhesive film is a single-sided adhesive film, whichis an ordinary scotch tape and easy to operate during the production.

The above step S2b is specifically forming an opening corresponding tothe conductive silver paste on the adhesive layer by using laserdrilling process.

Further, step S2c specifically includes: arranging the metal wire on theadhesive layer by using a wiring machine.

In addition, it may be understood that when the metal wire is arrangedon the adhesive layer, at least part of the structure of the lappingportion on the metal wire is located in the opening, and the openingcorresponds to the conductive silver paste. In this way, after theadhesive layer provided with metal wires is connected to the substrate,the lapping portion is aligned to the conductive silver pastecorresponding to the lapping portion. This facilitates the electricalconnection between lapping area and the conductive silver paste, therebyachieving the electrical connection between the metal wire and theelectrode.

The electrode is led out by disposing the conductive silver paste, so asto increase a contact area of the electrical connection between theelectrode and the metal wire, thereby enhancing the stability of theelectrical connection between the metal wire and the electrode.

It may be understood that, after the adhesive layer provided with metalwires is bonded to the substrate, a side provided with the metal wireson the adhesive layer and a side provided with the electrode layer onthe substrate are disposed opposite to and abutting against each other,so as to indirectly arrange frame traces for electrical connection tothe electrode layer in the frame trace area of the substrate. Inaddition, the lapping portion is aligned to the conductive silver pastecorresponding to the lapping portion, so that the lapping portion iselectrically connected to the corresponding conductive silver pastesubsequently.

It may be understood that, in step S3 of the second implementation,during the welding, a corresponding welding head is extended from theopening. Under the action of welding heat, the insulation layer of thelapping portion is removed. The lapping portion and the correspondingconductive silver paste are welded together, thereby achieving theelectrical connection between the lapping portion and the correspondingconductive silver paste.

In a specific implementation of preparing a touch sensor according tothe second implementation of the present invention, the preparationmethod is as follows.

A substrate having a conductive film is prepared or a conductive film isformed on the substrate. The conductive film is etched by using a laserprocess to form an electrode layer in the window area of the substrate.After the etching by using the laser process, the conductive silverpaste electrically connected to the electrode in the electrode layer isprinted in the frame trace area of the substrate. In addition, the OCAfor bonding is prepared, an opening is formed on the OCA by using laser,and then copper wires are arranged on the OCA by using a wiring machine.After the copper wires are arranged, the OCA bonded to the substrate. Atthis point, a side of the OCA having the copper wire is arrangedopposite to a side provided with the electrode layer on the substrate,and the opening corresponds to the conductive silver paste. After thebonding, the insulation layer of the lapping portion of the copper wireis removed by means of welding, and the lapping portion and thecorresponding conductive silver paste are welded together and connected.Finally, a silver paste is dispensed, by using a dispenser, at a jointbetween the lapping portion of the copper wire and the conductive silverpaste to protect a solder joint between the lapping portion and theconductive silver paste.

It may be understood that, the touch display screen includes two touchsensors. One touch sensor serves as a driving layer, and another servesas a receiving layer, to sense human body touch signals in cooperationwith work to complete the positioning of the touch position. In thisway, the OCA can bond the driving layer and the receiving layer. Afterthe bonding, the structure of the touch display screen is successively acover plate+the touch sensor as the receiving layer+the touch sensor asthe driving layer. It may be understood that, the OCA on the touchsensor as the receiving layer bonds the touch sensor as the receivinglayer and the cover plate, and the OCA on the touch sensor as thedriving layer bonds the driving layer and the receiving layer.

In addition, the methods for preparing the driving layer and thereceiving layer are the same, and both the driving layer and thereceiving layer can be prepared by using the preparation method in theabove second implementation.

It may be understood that, when the adhesive layer is apressure-sensitive adhesive film, the structure of the touch sensorafter the final bonding is successively: the cover plate+the OCA+thetouch sensor as the receiving layer+the OCA+the touch sensor as thedriving layer.

In addition, the corresponding method for preparing a touch sensor whenthe adhesive layer is a pressure-sensitive adhesive film is similar tothe method when the adhesive layer is the OCA. Therefore, details willnot be described herein again.

In the third implementation of the present invention, the method forpreparing a touch sensor in the third implementation differs from thatin the first implementation only in steps S2 and S3, and the other stepsS1 and S4 are the same. Details will not be described herein again.

In this implementation, step S2 specifically includes the followingsteps.

S2A: A conductive silver paste electrically connected to the electrodeis formed in the frame trace area and/or A conductive silver paste canelectrically connected to the electrode is formed on the adhesive layer,where the conductive silver paste contains a propylene glycol monomethylether solvent, a benzene solvent, a butyl cellosolve acetate (BCA)solvent, a diethylene glycol butyl ether acetate solvent, a carbitolacetate solvent, an isophorone solvent, or the like.

S2B: Forming an opening in the adhesive layer.

S2C: Arranging metal wires at a position of the adhesive layercorresponding to the frame trace area, where at least part of astructure of the lapping portion is located in the opening, and thematerial of the insulation layer is acrylic resin, polyurethane resin,epoxy resin, polyethylene, polypropylene, polyvinyl chloride,polystyrene, polymethyl methacrylate, polyester, polyoxymethylene,polyamide, polyphenylene ether, or the like.

S2D: Assembling the adhesive layer with metal wires onto the substrate.

The opening corresponds to the conductive silver paste. The conductivesilver paste in contact with the lapping area is a to-be-curedconductive silver paste.

S2A, S2B, S2B, and S2D are just for the convenience of description anddo not represent the sequence of steps. The sequence of step S2A andstep S2B can be transposed or can be performed simultaneously, and thesequence of step S2A and step S2C can be transposed or can be performedsimultaneously, as long as it is ensured that the opening finallycorresponds to the conductive silver paste. As a result, step S2C isafter step S2B, and step S2D is after step S2C. In addition, the stepnumbers in this application are all for convenience of description, andunless otherwise specified, each number does not represent a sequence.

In a specific implementation, the conductive silver paste contains BCA.Certainly, the present invention is not limited thereto.

Specifically, the adhesive layer in this implementation is the same asthe adhesive layer in the second implementation, which may be an OCA ora pressure-sensitive adhesive film. The structure of the touch displayscreen after the final bonding is also the same. Details will not bedescribed herein again.

The above step S2B is specifically forming an opening corresponding tothe conductive silver paste on the adhesive layer by using a laserdrilling process.

Further, step S2C specifically includes: arranging the metal wire on theadhesive layer by using a wiring machine.

In a specific implementation, in step S2A, a to-be-cured conductivesilver paste electrically connected to an electrode is formed in theframe trace area. In addition, when the metal wire is arranged on theadhesive layer, at least part of a structure of the lapping portion onthe metal wire is located in the opening, and the opening corresponds tothe conductive silver paste. In this way, after the adhesive layerprovided with metal wires is connected to the substrate, the lappingportion is aligned to and in contact with the conductive silver pastecorresponding to the lapping portion. During the curing of theconductive silver paste, the BCA solvent in the conductive silver pastedissolves the insulation layer of the lapping portion, so that thelapping portion and the conductive silver paste are cured together,thereby achieving the electrical connection between the metal wire andthe electrode.

Certainly, it may be understood that, in step S2A, a to-be-curedconductive silver paste that can be electrically connected to theelectrode may also be formed on the adhesive layer. In this way, aftermetal wires are printed on the adhesive layer, the lapping portion is incontact with the corresponding to-be-cured conductive silver paste. Inthis way, after the adhesive layer provided with metal wires isconnected to the substrate, during the curing of the conductive silverpaste, the BCA solvent in the conductive silver paste dissolves theinsulation layer of the lapping portion, so that the lapping portion andthe conductive silver paste are cured together, thereby achieving theelectrical connection between the metal wire and the electrode. Inaddition, the conductive silver paste is electrically connected to theelectrode of the electrode layer.

Alternatively, in step S2A, the conductive silver paste may also beformed on both the adhesive layer and the frame trace area. It may beunderstood that, at this point, the conductive silver paste in the frametrace area may be cured or to be cured, as long as the conductive silverpaste of the adhesive layer is disposed to be cured to dissolve theinsulation layer of the lapping portion, thereby achieving theelectrical connection between the lapping portion and the conductivesilver paste in the frame trace area.

The electrode is led out by disposing the conductive silver paste, so asto increase a contact area of the electrical connection between theelectrode and the metal wire, thereby enhancing the stability of theelectrical connection between the metal wire and the electrode.

It may be understood that, except for the above solvents, the componentsof the conductive silver paste may be the same as those of the existingconductive silver paste, such as additives, silver particles, and thelike. Details will not be described herein again.

It may be understood that, after the adhesive layer provided with metalwires is bonded to the substrate, a side provided with the metal wireson the adhesive layer and a side provided with the electrode layer onthe substrate are disposed opposite to and abutting against each other,so as to indirectly arrange frame traces for electrical connection tothe electrode layer in the frame trace area of the substrate. Inaddition, the lapping portion is aligned to the correspondingto-be-cured conductive silver paste. In this way, during the curing ofthe conductive silver paste, the BCA solvent in the conductive silverpaste dissolves the insulation layer of the lapping portion, so that thelapping portion and the conductive silver paste are cured together,thereby achieving the electrical connection between the metal wire andthe electrode.

In this implementation, step S3 specifically includes the followingsteps.

The lapping portion is in contact with the to-be-cured conductive silverpaste.

During the curing of the conductive silver paste, the BCA solvent in theconductive silver paste dissolves the insulation layer of the lappingportion, and the lapping portion and the conductive silver paste arecured together.

It may be understood that, during the curing of the conductive silverpaste, the BCA solvent in the conductive silver paste dissolves theinsulation layer on the lapping portion, so that the lapping portion andthe conductive silver paste are cured together, thereby achieving theelectrical connection between the lapping portion and the correspondingconductive silver paste. That is to say, in this implementation, theelectrical connection is performed by using the BCA solvent in theconductive silver paste to destroy the wire insulation layer.

In a specific implementation of preparing a touch sensor according tothe third implementation of the present invention, the preparationmethod is as follows.

A substrate having a conductive film is prepared or a conductive film isformed on the substrate. The conductive film is etched to form anelectrode layer in the window area of the substrate. After the etchingby using the laser process, the to-be-cured conductive silver pasteelectrically connected to the electrode in the electrode layer isprinted in the frame trace area of the substrate. In addition, the OCAfor bonding is prepared, an opening is formed on the OCA by using laser,and then copper wires are arranged on the OCA by using a wiring machine.After the copper wires are arranged, the OCA bonded to the substrate. Atthis point, a side of the OCA having the copper wire is arrangedopposite to a side provided with the electrode layer on the substrate,and the opening corresponds to the conductive silver paste. After thebonding, during the curing of the conductive silver paste, the BCAsolvent in the conductive silver paste dissolves the insulation layer onthe lapping portion, so that the lapping portion and the conductivesilver paste are cured together, thereby achieving the electricalconnection between the lapping portion and the corresponding conductivesilver paste. Finally, a silver paste is dispensed, by using adispenser, at a joint between the lapping portion of the copper wire andthe conductive silver paste to protect a connection point between thelapping portion and the conductive silver paste.

It may be understood that a touch display screen includes two touchsensors. One touch sensor serves as a driving layer, and another servesas a receiving layer, to sense human body touch signals in cooperationwith work to complete the positioning of the touch position.

In addition, the methods for preparing the driving layer and thereceiving layer are the same, and both the driving layer and thereceiving layer can be prepared by using the preparation method in theabove third implementation.

In the fourth implementation of the present invention, the method forpreparing a touch sensor in the fourth implementation differs from thatin the first implementation only in steps S2 and S3, and the other stepsS1 and S4 are the same. Details will not be described herein again.

In this implementation, step S2 specifically includes the followingsteps.

S2x: A conductive silver paste electrically connected to the electrodeis formed in the frame trace area.

S2y: Arranging metal wires at a position of the adhesive layercorresponding to the frame trace area.

The lapping portion corresponds to the conductive silver paste.

S2x and S2y are just for the convenience of description and do notrepresent the sequence of steps. The sequence of step S2x and step S2ycan be transposed, as long as it is ensured that the lapping portionfinally corresponds to the corresponding conductive silver paste. Inaddition, the step numbers in this application are all for convenienceof description, and unless otherwise specified, each number does notrepresent a sequence.

In step S2x, the electrode in the electrode layer is led out bydisposing the conductive silver paste, so as to increase a contact areaof the electrical connection between the electrode and the subsequentmetal wire, thereby enhancing the stability of the electrical connectionbetween the metal wire and the electrode.

Specifically, step S2y specifically includes: arranging the metal wireon the adhesive layer by using a wiring machine.

In addition, the lapping portion is finally caused to correspond to theconductive silver paste, so that the lapping portion is electricallyconnected to the corresponding conductive silver paste subsequently.

Specifically, the adhesive layer in this implementation is the OCA, soas to be easily bonded to other components of the touch display screenby means of bonding. For example, the touch display screen includes twotouch sensors. One touch sensor serves as a driving layer, and anotherserves as a receiving layer, to sense human body touch signals incooperation with work to complete the positioning of the touch position.In this way, the OCA can bond the driving layer and the receiving layer.

In this implementation, step S3 specifically includes the followingsteps.

S31: An opening corresponding to the conductive silver paste is formedon the adhesive layer, and remove the insulation layer of the lappingportion.

S32: Assembling the adhesive layer with metal wires onto the substrate,the lapping portion is electrically connected to the correspondingconductive silver paste.

Specifically, step S31 of forming the opening corresponding to theconductive silver paste on the adhesive layer specifically includes:forming an opening corresponding to the conductive silver paste on theadhesive layer by using a laser drilling process.

It may be understood that the opening corresponds to the correspondingconductive silver paste, and the lapping portion corresponds to thecorresponding conductive silver paste, so that at least part of thestructure of the lapping portion is located at a position where anopening is to be formed. During the laser drilling, the laser maysimultaneously remove the insulation layer of the lapping portion at theopening. Therefore, after the adhesive layer provided with metal wiresis bonded to the substrate, a side provided with the metal wires on theadhesive layer and a side provided with the electrode layer on thesubstrate are disposed opposite to and abutting against each other. Theopening corresponds to the conductive silver paste, and the lappingportion without the insulation layer is directly in contact with theconductive silver paste, thereby achieving the electrical connectionbetween the lapping portion and the corresponding conductive silverpaste.

Compared with the second implementation, in the fourth implementation ofthe present invention, the metal wire is first arranged on the adhesivelayer, and then drilling is performed. In this way, the insulation layerof the lapping portion can be removed during drilling, so as to omit thesubsequent step of removing the insulation layer of the lapping portionand welding the lapping portion to the corresponding conductive silverpaste, thereby reducing the preparation costs.

In a specific implementation of preparing a touch sensor according tothe fourth implementation of the present invention, the preparationmethod is as follows.

A substrate having a conductive film is prepared or a conductive film isformed on the substrate. The conductive film is etched by using a laserprocess to form an electrode layer in the window area of the substrate.After the etching by using the laser process, the conductive silverpaste electrically connected to the electrode in the electrode layer isprinted in the frame trace area of the substrate. In addition, the OCAfor bonding is prepared, and copper wires are arranged on the OCA byusing a wiring machine. After the copper wires are arranged, an openingis formed on the OCA by using a laser, and the insulation layer of thelapping portion at the opening is removed. Then the OCA is bonded to thesubstrate. At this point, a side of the OCA having the copper wire isarranged opposite to a side provided with the electrode layer on thesubstrate, the opening corresponds to the conductive silver paste, andthe lapping portion is in contact with the corresponding conductivesilver paste. After the bonding, a silver paste is dispensed, by using adispenser, at a joint between the lapping portion of the copper wire andthe conductive silver paste to protect a connection point between thelapping portion and the conductive silver paste.

In addition, the methods for preparing the driving layer and thereceiving layer in the touch display screen are the same, and both thedriving layer and the receiving layer can be prepared by using thepreparation method in the above fourth implementation.

Based on the above, the touch sensor in the present invention uses metalwires with an insulation layer to replace the silver paste in thetraditional process to form frame traces, so as to prevent theelectrical contact between adjacent metal wires and cause shortcircuits. In this way, the distance between adjacent metal wires may be0, and even a plurality of metal wires may be stacked on each other.Therefore, the width of the frame trace area can be further reducedwithout increasing the preparation costs of the touch sensor

It should be understood that, although this specification is describedaccording to each implementation, each implementation may not includeonly one independent technical solution. The description manner of thisspecification is merely for clarity. This specification should beconsidered as a whole by a person skilled in the art, and the technicalsolution in each implementation may also be properly combined, to formother implementations that can be understood by a person skilled in theart.

The series of detailed descriptions listed above are merely specificdescriptions of feasible implementations of the present invention, andare not intended to limit the protection scope of the present invention.Any equivalent implementations or changes made without departing fromthe technical spirit of the present invention shall fall within theprotection scope of the present invention.

1. A touch sensor, comprising a substrate, an electrode layer located ona window area of the substrate, and a frame trace located in a frametrace area of the substrate, wherein the frame trace comprises aplurality of metal wires, and each metal wire comprises a metal wirebody electrically connected to a corresponding electrode in theelectrode layer and an insulation layer wrapped around an outerperiphery of the metal wire body.
 2. The touch sensor according to claim1, wherein a distance between adjacent metal wires is in a range of 0-20um.
 3. The touch sensor according to claim 1, wherein the plurality ofmetal wires are arranged in parallel or in a stacked manner.
 4. Thetouch sensor according to claim 1, wherein a material of the insulationlayer is acrylic resin, epoxy resin, polyurethane resin, polyethylene,polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate,polyester, polyoxymethylene, polyamide, or polyphenylene ether.
 5. Thetouch sensor according to claim 4, wherein the frame trace area has aconductive silver paste electrically connected to the electrode in theelectrode layer, and the conductive silver paste contains a propyleneglycol monomethyl ether solvent, a benzene solvent, a butyl cellosolveacetate (BCA) solvent, a diethylene glycol butyl ether acetate solvent,a carbitol acetate solvent, or an isophorone solvent.
 6. A method forpreparing a touch sensor, the method comprising the following steps: S1:forming an electrode layer in the window area of a substrate; S2:Arranging the frame trace for electrical connection with the electrodelayer in the frame trace area of the substrate, wherein the frame tracecomprises a plurality of metal wires, and each metal wire comprises ametal wire body and an insulation layer wrapped around an outerperiphery of the metal wire body; and S3: removing the insulation layerof the lapping portion on the metal wire, and electrically connectingthe lapping portion to the corresponding electrode in the electrodelayer.
 7. The method for preparing a touch sensor according to claim 6,wherein step S2 specifically comprises: S21: A conductive silver pasteelectrically connected to the electrode is formed in the frame tracearea and an adhesive layer on the conductive silver paste; and S22:arranging the metal wire on the adhesive layer; or step S2 specificallycomprises: S2a: A conductive silver paste electrically connected to theelectrode is formed in the frame trace area; S2b: forming an opening inthe adhesive layer; S2c: arranging metal wires at a position of theadhesive layer corresponding to the frame trace area, wherein at leastpart of the structure of the lapping portion is located in the opening;and S2d: Assembling the adhesive layer with metal wires onto thesubstrate; the opening corresponds to the conductive silver paste. 8.The method for preparing a touch sensor according to claim 6, whereinstep S3 specifically comprises: removing the insulation layer of thelapping portion by means of welding, and welding the lapping portion andthe corresponding conductive silver paste together, so that the lappingportion is electrically connected to the corresponding conductive silverpaste.
 9. The method for preparing a touch sensor according to claim 8,wherein the method for preparing a touch sensor further comprises S4after step S3: dispensing or printing a protective adhesive at a jointbetween the lapping portion and the conductive silver paste, wherein theprotective adhesive is silver paste.
 10. The method for preparing atouch sensor according to claim 6, wherein step S2 specificallycomprises: S2A: A conductive silver paste electrically connected to theelectrode is formed in the frame trace area and/or A conductive silverpaste can electrically connected to the electrode is formed on theadhesive layer, wherein the conductive silver paste contains a propyleneglycol monomethyl ether solvent, a benzene solvent, a BCA solvent, adiethylene glycol butyl ether acetate solvent, a carbitol acetatesolvent, or an isophorone solvent; S2B: forming an opening in theadhesive layer; S2C: arranging metal wires at a position of the adhesivelayer corresponding to the frame trace area, wherein at least part of astructure of the lapping portion is located in the opening, and thematerial of the insulation layer is acrylic resin, polyurethane resin,epoxy resin, polyethylene, polypropylene, polyvinyl chloride,polystyrene, polymethyl methacrylate, polyester, polyoxymethylene,polyamide, or polyphenylene ether; and S2D: Assembling the adhesivelayer with metal wires onto the substrate; the opening corresponds tothe conductive silver paste, and the conductive silver paste in contactwith the lapping portion is a to-be-cured conductive silver paste. 11.The method for preparing a touch sensor according to claim 10, whereinstep S3 specifically comprises: the lapping portion is in contact withthe to-be-cured conductive silver paste; and during the curing of theconductive silver paste, the conductive silver paste dissolves theinsulation layer of the lapping portion, and the lapping portion and theconductive silver paste are cured together.
 12. The method for preparinga touch sensor according to claim 11, wherein the method for preparing atouch sensor further comprises S4 after step S3: dispensing or printinga protective adhesive at a joint between the lapping portion and theconductive silver paste, wherein the protective adhesive is silverpaste.
 13. The method for preparing a touch sensor according to claim 6,wherein step S2 specifically comprises: S2x: A conductive silver pasteelectrically connected to the electrode is formed in the frame tracearea; S2y: arranging metal wires at a position of the adhesive layercorresponding to the frame trace area, wherein the lapping portioncorresponds to the conductive silver paste.
 14. The method for preparinga touch sensor according to claim 13, wherein step S3 specificallycomprises: an opening corresponding to the conductive silver paste isformed on the adhesive layer, and remove the insulation layer of thelapping portion; and assembling the adhesive layer with metal wires ontothe substrate, the lapping portion is electrically connected to thecorresponding conductive silver paste.
 15. The method for preparing atouch sensor according to claim 14, wherein the method for preparing atouch sensor further comprises S4 after step S3: dispensing or printinga protective adhesive at a joint between the lapping portion and theconductive silver paste, wherein the protective adhesive is silverpaste.